A brace from Lionel Messi at Emirates Stadium last month put Luis Enrique's men in poll position to advance beyond the round of 16 for the ninth straight season.
The Gunners' record in recent seasons, meanwhile, is less impressive and failure to overturn the scoreline in Barcelona would see them exit at this stage of the competition for the sixth season in succession.
"It's going to be a tough, tough ask but obviously we have to go there and believe we can cause an upset. We created chances to score in the first leg at home," Aaron Ramsey, who will miss the game through injury, told Goal.
What Arsenal must do in Barcelona
Should Arsenal crash out, however, they will become solely reliant on their league position to qualify for next year's tournament. Arsene Wenger has led his side into the Champions League for 18 straight seasons but they sit just three points above fith-placed West Ham in the top flight and risk missing out on the tournament next season if their recent league form continues.
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